I am running 18.04. I am on a network running a variety of systems but the philosophy is very apple. They are using Bonjour for discovery. This is not working on my box. If I ping a .local name I get "name or service not known". if I used avahi-browse -arl it just sits there and doesn't list anything.
I have looked at nsswitch.conf and tried various combinations of msdn and have removed the return on fail clause.
My adapter is a bridged tap interface to support kvm vm instances. Watching with Wireshark, on the ping, I can see mdns sending 3 qm questions for that address. I don't see a specific response. I can see other devices on the network talking mdns multicast.
I am not sure how to troubleshoot this further. I am guessing that the multicasts from my box are not getting across the bridge to the wire but am not sure.